A Grand Time

Another Blogging Milestone

The other day I made my one-thousandth post to this blog.  I didn’t know this milestone had passed until I logged in today and the helpful counter in the administrative area told me so. What a milestone to achieve with my post about Jupiter and its latest impact!  I’m grateful to all my readers who keep coming back. You’re why I write this stuff about the universe!

So, here in post 1,002, what should I write about?  Stargazing is always a good topic.  There’s nothing like a stroll under the night-time sky to inspire one’s thoughts toward cosmic ideas. We’ve been going out every night to watch the sunset and see who can spot Venus first.  It’s there, if you know where to look, and once the skies start to get kinda, sorta dark, the planet is blazing out like a beacon. The good thing about Venus is that you only need clear skies to see it because it’s bright in city skies as well as in the dark countryside. So, I encourage you to check out Venus in the evening.

Venus-gazing reminds me of a phone call we got at the planetarium back when I was a lecturer there.  It was from a person who was nearly terrified that the aliens were landing and that we (astronomers) hadn’t told anybody. I asked the caller what made them think the Earth was being invaded and they described how they had been watching this bright light in the western skies each night for a week and how that light got closer to the mountains each night and then disappear. They were sure that the alien ship was landing in the mountains each night. The caller was most upset when I explained that they were seeing the planet Venus set behind the mountains, just as the Sun did each night.  Well, I don’t know if they were upset at finding out what they were seeing or embarrassed at not having made the connection between the Sun setting behind the mountains and the planets (and stars) doing the same.

This was years before the Comet Hale-Bopp Heaven’s Gate cult madness and not long before I went back to school and spent some of my grad school years studying comets.  We were used to getting phone calls from the public about mysterious lights in the sky, but the imaginative stories some people told never failed to amaze (and sometimes sadden) me.

It seems that when it comes to the sky and understanding what’s in it, somehow some people suspend their common sense, their sense of disbelief, and will swallow anything.  I don’t know why that is. I just know that it happens.  Which is too bad, because actually studying and understanding how things in the sky work is a very satisfying and fascinating journey.  It’s not different from understanding (in general terms) how a car engine works or how a plane works.  If you want to know, you probably ask somebody who works on cars, or you find a book on how planes fly.  You seek to understand the physical reasons why the car runs and the plane flies.

We wouldn’t tell somebody that a car works by magic or that a plane goes up into the air because of magical spirits that lift it up, would we?  So, why, upon seeing a bright light in the sky, did a person jump to an unsupported conclusion that it was a shipload of LGMs on some kind of tour of the planets?  Why did the Heaven’s Gaters decide that a known comet was a mothership?  They didn’t use common sense — well, let me say that the person who called me at the planetarium at least wanted to know what the light really was. The Heaven’s Gaters didn’t want to know (0r couldn’t let themselves find out) what Comet Hale-Bopp really was.

Certainly stargazing lights some amazing thought-fires in your brain.  It certainly does in mine, and I’ve been lucky to be able to share those thoughts with readers since early 2002. It’s been a grand time doing a grand of postings!

Sculpting a Galaxy

in Sculptor

Wow!  Take a look at this beauty of an image from the European Southern Observatory’s VISTA telescope.

ESO VISTA's view of the galaxy NGC 253, which lies about 13 million light-years from Earth. Click to massively galacticate. Courtesy ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit.

What you’re seeing here is a VISTA view of the galaxy NGC 253, a.k.a. the Sculptor Galaxy, found in the constellation Sculptor (visible in Southern Hemisphere skies).  VISTA looked at this galaxy in infrared light, which gave it a great view of the rich collection of dust clouds that thread through the spiral arms of the galaxy. These dust clouds are where star formation takes place.  In fact, NGC 253 is a starburst galaxy, one that has undergone waves of star formation.  Tracing the dust clouds and bursts of starbirth allows astronomers to understand the formation history of the galaxy and the actions that have shaped it into the barred spiral we see today.

The telescope also was able to see a population of cool, red stars that aren’t very visible (if at all) in optical wavelengths of light (which are the main wavelengths our eyes can see).    This is what infrared viewing allows astronomers to do — that is, to peer through the veils of dust that hide the details of the Sculptor Galaxy. Now they can study in deeper detail the myriad of cool red giant stars in the halo that surrounds the galaxy, and measure the composition of some of NGC 253’s small dwarf satellite galaxies. And, they can search for new objects such as globular clusters and ultra-compact dwarf galaxies that would otherwise be invisible without the deep VISTA infrared images.

I remember some years ago when we first started seeing boasts by ground-based observatories that, using new (at the time) technologies such as adaptive optics, astronomers would be able to achieve “near-Hubble” quality observations of such things as the Sculptor Galaxy.  Images like this, from a ground-based observatory in Chile, show that it can be done.  And, the exciting part is that using observatories like this and the newly improved Hubble Space Telescope, our view of the cosmos is only going to get better!

Exploring Science and the Cosmos

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